<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div{
            width: 100px;
            height: 100px;
            border: 1px solid red;
        }
        #d1{
            /*margin-left: 50px;*/
            /*margin: 50px; !*四个方向赋值*!*/
            /*margin: 10px 50px;!*上下10  左右50*!*/
            /*margin: 10px 20px 30px  40px;!*上右下左顺时针赋值*!*/
            margin-bottom: 20px;
        }
        #d2{
            /*上下相邻两个元素彼此添加外边距，取最大值*/
            margin-top: 60px;
        }
        span{
            border: 1px solid blue;
        }
        #s1{
            margin-left: 30px;
            margin-right: 20px;
            /*行内元素外边距无效*/
            margin-top: 50px;
        }
        #s2{
            margin-left: 20px;
        }
    </style>
</head>
<body>
<span id="s1">span1</span>
<span id="s2">span2</span>
<div id="d1">div1</div>
<div id="d2">div2</div>
</body>
</html>